1. Field of the Invention
This invention relates to the electrical arts. In particular, this invention relates to a control device for the control of at least one controllable media device, a system incorporating the control device and a method of using the control device.
2. Description of the Related Art
As media displays are not only becoming more elaborate and complex, but are becoming more commonplace, the control of the controllable media devices used in creating the displays must become more versatile. To this end, controllable media devices with automated and remotely controllable parameters are known in the entertainment and architectural lighting markets. Such media devices are commonly used in theaters, television studios, concerts, theme parks, night clubs and other venues. Representative controllable media devices include lighting devices, such as luminaires and dimmers, projection devices, video processors, audio devices, media servers, effects systems, such as fog machines, and the like. So, for example, a typical controllable lighting device will, at least, provide remote control over intensity, color, focus, beam pattern and zoom. Controllable lighting devices may further provide remote control over pan and tilt among other parameters. Similarly, a typical controllable projector will, at least, provide remote control over intensity, zoom, focus and input selection.
It is a difficulty in elaborate media displays, that the different controllable media devices are often controlled by different protocols. Today many controllable devices are controlled by command-based protocols, including the RS-232 protocol, a command-based protocol commonly used for projectors, video processors/switchers, and playback devices, the RS-422 protocol and, in particular, the Sony Decklink extended RS-422 protocol, commonly used to trigger playback devices, such as analog and digital VTR decks, media servers and the like, as well as certain Ethernet-based protocols.
It is also known to control certain controllable media devices through the industry standard state-based protocols, such as DMX-512. DMX-512 was developed by the United States Institute of Theatre Technology (USITT) in 1986 and has since been adopted and revised by the Entertainment Services and Technology Association (ESTA) as an ANSI standard, E1.11. This is an EIA RS-485 based serial network protocol designed to transmit 512 bytes of data (or channels) from a DMX-512 controller to a number of serially connected media device controllers.
A controllable media device controller that uses DMX-512 for control uses a number of discrete channels to control various media device parameters. Each controllable media device is designed by its manufacturer with a number of such controllable parameters that respond to a pre-defined mapping of the channels. Typically, the assignment mapping of DMX-512 channels to the internal control channels and hence to physical parameters is fixed within the media device. For example, channels 1 and 2 may control pan and tilt, 3 may control zoom and so on. Additionally, each of the channels has multiple levels, or amplitude settings, to produce different values for the parameters within the channels. The amplitude level on each channel can be set to one of up to 255 discrete levels. The mappings of the values within the channels to particular commands for a parameter are also fixed within the media device.
It is a drawback of such DMX-512 and other state-based protocol controllable devices, that the controller has control over all exposed parameters whether all the parameters are to be used or not. This results in the user often changing parameters that should not be modified. With a DMX-512 controllable projector, for example, the user may want control over only intensity and input selection, but not zoom or focus, so that a controller user will not inadvertently adjust parameters, that a projectionist may have spent hours manually setting.
A manufacturer may offer more than one such mapping selectable as a different “protocol mode” or “library” option. It remains a drawback, however, that the user cannot freely decide which parameters to use. It is a further drawback of this approach that the library file format is different for every brand/type of control requiring the media device controller include a large number of library files in order to support multiple media devices.